1. Field of the Invention
The present invention relates to a caulking gun, and more particularly to a caulking gun having an angle adjustment function.
2. Description of the Related Art
A conventional caulking gun in accordance with the prior art shown in FIGS. 7 and 8 comprises a gun body 60 having a first end formed with a mounting hole 63 and a second end formed with a handle 61, a push rod 80 movably mounted on the gun body 60 and extended through the mounting hole 63 of the gun body 60, a push plate 90 mounted on the push rod 80 in an inclined manner and having a first end formed with a locking hole 91 rested on the push rod 80, an elastic member 82 mounted on the push rod 80 and biased between the gun body 60 and the push plate 90, a piston lever 64 pivotally mounted on the gun body 60 and having an end provided with a link 65 rested on a second end 92 of the push plate 90 to push the push plate 90 to move, a barrel 70 mounted on a side of the gun body 60 and having an inside formed with a receiving chamber 71, a pull knob 81 mounted on a first end of the push rod 80, a catch plate (not shown) mounted on a second end of the push rod 80 and movably mounted in the receiving chamber 71 of the barrel 70, and a cartridge (not shown) containing silicone received in the receiving chamber 71 of the barrel 70 and rested on the catch plate.
When the piston lever 64 is pressed, the link 65 of the piston lever 64 is urged on the second end 92 of the push plate 90 to push the push plate 90 to move forward in an inclined manner. Thus, the locking hole 91 of the push plate 90 is locked on the push rod 80 in a tilt manner to move the push rod 80 which moves the catch plate to compress the cartridge. After the piston lever 64 is released, the push plate 90 is pushed by the restoring force of the elastic member 82 to move backward in a horizontal manner without moving the push rod 80. Thus, the push rod 80 and the catch plate are moved forward successively by pressing the piston lever 64 repeatedly to compress the cartridge so as to squeeze the silicone outward from the cartridge for use.
However, when the locking hole 91 of the push plate 90 is worn out during a long-term utilization, the diameter of the locking hole 91 of the push plate 90 is expanded, so that the locking hole 91 of the push plate 90 cannot lock the push rod 80 to move the push rod 80. Thus, the conventional caulking gun cannot be used when the locking hole 91 of the push plate 90 is worn out, thereby decreasing the lifetime of the conventional caulking gun.